An unmanned aerial vehicle (UAV), commonly known as a drone and also referred to as an unpiloted aerial vehicle and a remotely piloted aircraft (RPA) by the International Civil Aviation Organization (ICAO), is an aircraft without a human pilot aboard. ICAO classify unmanned aicraft into two types under Circular 328 AN/190

Autonomous aircraft: are considered to be not suitable for regulation due to legal and liability issues

Remotely piloted aircraft are subject to civil regulation under ICAO and under the relevant National aviation authority

There are many different names for these aircraft. They are called UAS (unpiloted air system), UAV (unpiloted aerial vehicle), RPAS (remote piloted aircraft systems) and model aircraft. It has also become popular to refer to them as drones. Their flight is controlled either autonomously by onboard computers or by the remote control of a pilot on the ground or in another vehicle. The typical launch and recovery method of an unmanned aircraft is by the function of an automatic system or an external operator on the ground. Historically, UAVs were simple remotely piloted aircraft, but autonomous control is increasingly being employed.

They are usually deployed for military and special operation applications, but also used in a small but growing number of civil applications, such as policing and firefighting, and nonmilitary security work, such as inspection of power or pipelines. UAVs are often preferred for missions that are too "dull, dirty or dangerous" for manned aircraft.

REMOTELY pilotED AIRCRAFT